The temporary creation of hairstyles for a longer period of time lasting up to a number of days generally requires the use of firming active substances. Hair treatment agents that serve to temporarily shape the hair thus play an important role. Appropriate agents for temporary deformation usually contain synthetic polymers and/or waxes as firming active substance. Agents for assisting the temporary reshaping of keratin-containing fibers can be produced, by way of example, in the form of hairspray, hair wax, hair gel or hair mousse.
The most important property of an agent for temporarily deforming hair, also referred to hereinafter as a styling agent, lies in being able to provide the treated fibers with the greatest possible hold in the newly modeled form—i.e. a form impressed on the hair. Reference is also made to a strong hairstyle hold or to a high holding power of the styling agent. The hold of a hairstyle is determined fundamentally by the type and quantity of the used firming active substances, however the further constituents of the styling agent can also have an effect.
Besides a high holding power, styling agents must also satisfy a wide range of further requirements. These can be divided roughly into properties on the hair, properties of the respective formulation, for example properties of sprayed aerosols, and properties that concern the handling of the styling agent, wherein the properties on the hair are attributed particular importance. In particular, moisture resistance, low stickiness (tack), and a balanced conditioning effect can be cited. Furthermore, a styling agent should be universally usable for all hair types where possible and should be mild on the hair and skin.
In order to satisfy the different requirements, a multiplicity of synthetic polymers which are used in styling agents have been developed as firming active substances. These polymers can be divided into cationic, anionic, non-ionic and amphoteric firming polymers.
European patents EP 1719499 B1, EP 1719500 B1 and EP 1726331 B1 describe acrylate resins with the INCI name Acrylates/Hydroxy Ester Acrylates Copolymer and use thereof in styling agents. International patent application WO 2012/054278 A2 also mentions Acrylates/Hydroxy Ester Acrylates Copolymers as hair-firming polymers and, as an example, uses Acudyne® 1000 (The Dow Chemical Company) in hair mousses.
Hair-firming agents based on copolymers of styrene with (meth)acrylic acid and/or esters thereof are described in international patent application WO2012/168035 A1.
Not any polymer or not any polymer blend is suitable in principle for the production of hair-styling agents. This is true in particular for hairsprays, in which case the viscosity for example and thus also the spray behavior is influenced by the polymer or the quantity of the used polymer.
Furthermore, not any polymer and any polymer mixture are suitable for producing highly concentrated hair-styling agents. Besides the previously described problems with the viscosity and dosing of the agents, difficulties also occur with regard to the solubility and the storage stability, in particular of hairsprays, with rising polymer concentration.
A hairspray with high polymer content (compact hairspray) is described for example in international patent application WO 2005/012588 A2.
Although suitable polymers and polymer combinations have been developed for some time now for use in styling concentrates in the field of temporary hair deforming, the previously attained results still have room for improvements, in particular with regard to the storage stability, application, and the holding power of these agents. In particular, currently obtainable styling agents can still be improved insofar as a good combination of holding power and long-term hold (High Humidity Curl Retention) is not always sufficiently ensured.